gif

commit f36428b8423044e87ca61ec0c92e18e7b0189a2d
parent f7f433a8843945a41af0904de22ef0b98e2cad88
Author: phoebos <ben@bvnf.space>
Date:   Wed,  1 Sep 2021 19:04:46 +0100

cast to uint16_t for LSB values instead of mess

I have to say, it's neat how C can do this.

Diffstat:
M
gif.c
 | 
18
++++++++++++++----

1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/gif.c b/gif.c
@@ -8,6 +8,7 @@
 #include <math.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -19,8 +20,8 @@
 typedef unsigned char rgb[3];
 struct Gif {
     char version[3]; /* 87a or 89a */
-    int width;
-    int height;
+    uint16_t width;
+    uint16_t height;
     unsigned char flags; /* ABBBCDDD
                             A: global colour table [GCT] flag
                             B+1: colour resolution (bits per primary colour)
@@ -69,8 +70,17 @@ gif_decode(unsigned char *buf, size_t len){
     fprintf(stderr, "GIF version %s, ", g.version);
     buf += 3;
     len -= 3;
-    g.width =  *buf++ | *buf++ << 2;
-    g.height = *buf++ | *buf++ << 2;
+
+    uint16_t *tmp;
+
+    tmp = (uint16_t *)buf;
+    g.width = *tmp;
+    buf += 2;
+
+    tmp = (uint16_t *)buf;
+    g.height = *tmp;
+    buf += 2;
+
     fprintf(stderr, "%d x %d\n", g.width, g.height);
 
     g.flags = *buf++;